Method and apparatus for crimping yarn



Feb. 24, 1959 E. J. GRISET, JR 2,874,443

METHOD AND APPARATUS FOR CRIMPING YARN Filed May 12, 195:5

INVENTOR lines/J finke'd ATTORNEY United. States atent O METHOD AND APPARATUS FOR 'CRIMPING YARN Ernest J. Griset, Jr., Asheville, N. C., assignor, by mesne assignments, to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware Application May 12, 1953, Serial No. 354,503

Claims. (Cl. 28-1) This invention relates to the manufacture of yarn and more particularly to an improved method and apparatus for producing curled yarn.

In copending application Serial No. 237,526 of Ernest J. Griset, filed July 19, 1951, (now Patent No. 2,661,588) of which the present application is a continuation-in-part, there is disclosed an improved suction-type thread collection device. It has now been discovered that this type device may be utilized to impart a curliness and bulkiness to a continuous strand of twisted or untwisted yarn.

The operation of the present invention will be apparent from the following detailed description when considered in conjunction with the accompanying drawings wherein:

Figure 1 is a schematic illustration of one embodiment of the present invention;

Figure 2 is a perspective of another embodiment of the present invention;

Figure 3 is a sectional view taken along the central axis of the thread collection device and illustrates a third embodiment of the present invention;

Figure 4 is a' schematic illustration of an apparatus for practicing the present invention which utilizes a special yarn feed mechanism; and

Figure 5 is a schematic drawing in elevation of the yarn feed mechanism in Figure 4.

In general, the desired properties are introduced into the yarn in the present invention by passing the continuously running yarn into and through the suction device and by changing the direction of travel of the yarn after it emerges from the nozzle of the suction device and while it is still under the influence of the stream of air passing through the device. Preferably, the direction of travel is changed by disposing a bafile member opposite the nozzle of the suction device and causing the yarn to impinge thereon. The yarn is then collected in package form on any suitable take-up.

By controlling the respective rates at which the yarn is fed to and withdrawn from the suction device, for example, by feeding yarn into the suction device by a freely rotatable means operating in response solely to the withdrawal of yarn therefrom, a most unusual effect is obtained. The yarn treated according to the present invention is characterized by having a pronounced curliness and bulkiness throughout the continuous strand. It thus has properties in common with spun yarn and, in fact, a fabric woven with the present type yarn used as a filling has the same bulkiness and soft feel as a fabric woven from spun yarn.

Referring now to Figure 1, the numeral 10 designates a source of supply for a continuously running yarn 11. The yarn is passed through guide 12 and introduced into the low pressure area of a suction type thread collecting device 13. Further details of the device 13 will be obvious from the discussion of Figure 3 below. Air or other gas from any suitable source is introduced into the device 13 through tube 14. The yarn 11 is caught in the ice jet of gas and propelled through tube 15 of suction device 13. a

A flat impervious bafile plate 16 mounted by means not shown is disposed a short distance away from the end of the tube 15. It will be noted that the baflle 16 is inclined at an angle with respect to a perpendicular to the tube 15. With this arrangement, the yarn is discharged from the end of the tube 15 and into contact with the batile 16 where it continues to be subjected to a turbulence due to the blast of air. The yarn 11 is then withdrawn via thread guides 17 and 18 to take-up 19. It is important that the take-up 19 withdraw the yarn 11 from the vicinity of the bathe 16 at a much slower speed than it is fed to the suction device 13. In other words, it is necessary that a certain amount of slack accumulate in the yarn in the vicinity of the deflector plate and during the time that it is under the influence of the blast of air.

The yarn collected on the take-up 19 has properties completely dilferent from those possessed by the yarn supplied to the suction device 13. For example, a 450/ viscose rayon filament yarn containing a twist of 3 T. P. I. after being subjected to the foregoing process is transformed from a smooth constant denier yarn into a yarn having the general appearance and feel of spun yarn. The described process does not actually sever individual filaments of yarn. Instead, the blast of air acts with varying severity on the various filaments with the result that numerous small curls are introduced throughout the length of the yarn. Cloth woven using yarn so treated as filling was found to have a bulky appearance with a fuzzy or loopy surface.

In Figure 2, the member 13 is provided with a thread guide 26 mounted on the bottom side thereof. The yarn 11 to be treated is introduced into the tube 15 and expelled therefrom by means of a'stream of air entering at 14. Upon emerging from tube 15 the direction of travel of'the yarn 11 is changed by passing it through thread guide 26 and to a suitable take-up. As previously explained, the yarn is withdrawn by the take-up considerably slower than it is supplied to the suction device 13. Thus, the yarn between the exit end of tube 15 and guide 26 has a certain amount of slack in it. It is, of course, not necessary that thread guide 26 be attached directly to suction device 13. Any suitable means for supporting thread guide 26 may be used, its principal function being to change the direction of travel of the yarn as it emerges from the tube 15.

Figure 3 shows the details of the thread suction device 13. The numeral 20 indicates generally a solid cylindrical support or housing in which a jet 21 and discharge tube .22 are maintained in spaced axial registry separated by a small gap. A notch cut in the housing 20 is defined by an inclined shoulder 23 and a perpendicular shoulder 24. The jet 21 projects through the shoulder 23 and an aligned aperture in the shoulder 24 leads to the tube 22.

The jet 21 is provided internally with two bores of different diameter. The larger bore 25 extends from the outer end about half way along the jet tube. The smaller bore 29 extends to the tip portion of-the jet. The twobore assembly is held in place in housing 20 by means of a threaded section 30 on'the exterior of the jet 21 in a radial plane coinciding with a part of the length of large bore 25.

Air from any suitable source is connected at 34 to the large bore end of jet 21. The air emerges from the tip of jet 21 at a high velocity, enters discharge tube 22 and finally is emitted to the atmosphere. The high ve- Iocity stream of air creates a reduced pressure zone in the notch formed by the shoulders 23 and.24 with the result that any yarn placed in the wedge-shaped portion is immediately conveyed into the stream of high velocity air and propelled into the tube 22.

In Figure 3, a sphere 33, disposed opposite the exit end of tube 22, serves as the deflecting means for the air and yarn. As in the foregoing embodiments, it is necessary that the yarn be withdrawn from the vicinity of sphere 33 at a rate considerably less than that at which it is supplied to the suction device 13.

Figures 4 and 5 illustrate one means of controlling the rate at which the yarn is fed to the suction device and withdrawn therefrom. Yarn 40 is withdrawn from a source 41 by means of feed roll 42 and supplied to suction device 43 at a rate depending on the speed of rotation of roll 42. Upon emerging from tube 44, the yarn 40 strikes deflector plate 45 where the path of travel is directionally changed and it is then led by way of guides 46, 47 and 48 to a take-up 49. Shaft 52 of take-up 49, rotatably mounted in housing 53, is driven by any suitable means (not shown).

It will be seen from Figure 5 that freely rotatable roller 50 lies in contact with the rotating take-up 49 and is surface driven by the take-up 49 or the package of yarn carried thereon. By the use of this system, freely rotatable roller 50 derives a rotational energy from the driven takeup 49, which energy is utilized as the sole means for feeding yarn into the suction device at a rate which is continuously proportionate, and at a constant ratio, to the rate of withdrawal from said device. Feed roll 42 is about larger in diameter than the average diameter of roller 50 and is driven by roller 50 to which it is connected. Roller 50 is rotatably mounted on movable arm 51 for sliding movement up and down, depending on the size of the package carried on the take-up 49. In view of the size of feed roll 42, the yarn 40 will always be supplied to the suction device 43 at a rate about 25% faster than it is withdrawn by the take-up 49. As the package builds up on the take-up 49 and the peripheral speed of roller 50 increases, the speed of feed roll 42 increases at an identical rate.

It will be seen that the apparatus disclosed in Figures 4 and 5 not only controls the rate at which the yarn is supplied to the suction device and withdrawn therefrom but also automatically compensates for the change in the take-up speed as the take-up package increases in size. By the use of this apparatus a substantially uniform curl or bulkiness is given to the yarn throughout the entire package.

Best results are obtained in practicing the present invention if the yarn is supplied to the suction device between about 5% and 40% faster than it is withdrawn therefrom, depending on the size of the yarn being treated and the rate of feed. For example, a very satisfactory curl is obtained with 600/120 viscose rayon yarn if it is supplied to the suction device between about 8 and 34% faster than it is withdrawn therefrom. With 450/80 viscose rayon, a satisfactory range is between 7% and Good results are obtained by taking the yarn up at a rate of about 100 meters per minute. The present invention may be used to curl either twisted or untwisted yarn. If desired, a quick drying soluble lacquer may be sprayed onto the yarn either before it enters the air stream, during the time it is in the air stream or after it leaves the air stream. This is by no means essential, but it is helpful as it tends to hold the curls in place during processing. After the yarn is woven, the lacquer may be removed by washing.

It is to be understood that the scope of the invention is only to be limited by the appended claims.

What is claimed is:

1. Apparatus for the treatment of yarn comprising a tube through which yarn is passed, means for establishing a high velocity stream of gas in said tube, rotatable means to withdraw yarn issuing from said tube, and freely rotatable means operative in response to the withdrawal 4 of yarn by said rotatable means for feeding succeeding portions of yarn into said tube.

2. Apparatus for producing a curly yarn comprising a jet means through which yarn is passed, means to supply gas under pressure to said jet means, a rotatable collection device for withdrawing yarn from said jet means and freely rotatable means operative in response to the withdrawal of yarn by said collection device for feeding yarn to said jet means at a rate proportionate to the rate of withdrawal.

3. Apparatus for the treatment of yarn comprising a jet means through which yarn is passed, rotatable means to collect yarn issuing from said jet means and freely rotatable means driven by yarn collected on said rotatable means to feed succeeding portions of yarn into said jet means at a rate proportionate to the rate of collection.

4. Apparatus for producing a curly yarn comprising a jet means having a passageway through which yarn is passed, means for establishing a high velocity stream of gas in said passageway, means in spaced axial alignment with said passageway for deflecting yarn issuing from said jet means, rotatable means to collect yarn impinging on said deflecting means and freely rotatable means driven by yarn collected on said rotatable means to feed succeeding portions of yarn into said jet means at a rate proportionate to the rate of collection from said deflecting means.

5. Apparatus for producing a curly yarn comprising a jet means having a tubular passageway through which yarn is passed, means for establishing a high velocity stream of gas in said passageway, means in spaced axial alignment with said passageway for deflecting yarn issuing from said jet means, rotatable means to collect yarn impinging on said deflecting means and freely rotatable means driven by contact with the yarn collected on said rotatable means to feed succeeding portions of yarn into said jet means at a linear speed at least 5% greater than it is withdrawn from said deflecting means.

6. In the method of curling yarn which is passed through a high velocity stream of gas and collected on a take-up device, the improvement which comprises feeding yarn into the stream by a freely rotatable roller driven solely by yarn collected on said take-up device 7. In the method of curling a continuous multifilament yarn which is passed through a high velocity stream of gas and withdrawn therefrom the improvement which comprises feeding yarn into the stream at a rate greater than that of withdrawal by a freely rotatable roller driven solely by said withdrawn yarn.

8. The method of producing curly yarn comprising the steps of establishing a stream of gas flowing at a high velocity, introducing multifllament yarn into said stream, withdrawing the yarn from said stream and collecting the same on a take-up device, deriving a rotational energy from the take-up device and feeding yarn into said stream at a rate proportionate to the rate of take-up by use of said rotational energy.

9. The method of producing curly yarn comprising the 7 steps of establishing a stream of gas flowing at a high velocity, introducing multifilament yarn into said stream, impinging said stream of gas and said yarn on a deflecting plate, withdrawing the yarn from said deflecting plate and collecting the same on a driven take-up device, deriving a rotational energy from the take-up device and feeding yarn into said stream at a rate greater than that of take-up by use of said rotational energy.

10. The method of producing curly yarn comprising the steps of establishing a stream of high velocity gas flowing in a straight line, introducing multifilament yarn continuously into said stream, impinging said stream of gas and said yarn on a deflecting plate, withdrawing the yarn from said deflecting plate and collecting the same on a driven take-up device, deriving a rotational energy from the take-up device and feeding yarn into said stream at a rate at least 5% greater than it is withdrawn from the deflecting means by use of said rotational energy.

References Cited in the file of this patent UNITED STATES PATENTS PO01 Oct. 29, 1940 

